Abrupt Flushing of High-Density Core in Internal Diffusion Barrier Plasmas and its Suppression by Plasma Shape Control in LHD
スポンサーリンク
概要
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Abrupt flushing of central density occurs in internal diffusion barrier (IDB) plasmas in the Large Helical Device (LHD), where a super dense core (SDC) of the order of 1020 m-3 is formed inside; this event is called “core density collapse (CDC).” CDC must be suppressed as further increase of the central pressure is inhibited. Since CDC is always accompanied by a large Shafranov shift of the plasma center, it has been supposed that mitigation of the Shafranov shift might affect CDC. Vertical elongation of the plasma shape (κ > 1) is effective in mitigating the Shafranov shift, and κ can be controlled with the quadrupole magnetic field BQ. To examine the impact of plasma shape control on CDC, BQ scan experiment has been performed in the LHD. The large Shafranov shift in IDB plasmas is mitigated by increasing κ. As a result, CDC is suppressed and high central β values of approximately 7% have been achieved in vertically elongated plasmas. The optimum κ varies with the magnetic configuration. Beta gradients greater than those at CDC in the κ = 1 configuration are observed without CDC in vertically elongated plasmas.
著者
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OHYABU Nobuyoshi
National Insitute for Fusion Science
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KOMORI Akio
National Insitute for Fusion Science
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YAMADA Hiroshi
National Insitute for Fusion Science
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FUNABA Hisamichi
National Insitute for Fusion Science
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GOTO Motoshi
National Insitute for Fusion Science
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MASUZAKI Suguru
National Insitute for Fusion Science
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MORITA Shigeru
National Insitute for Fusion Science
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NARIHARA Kazumichi
National Insitute for Fusion Science
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OHDACHI Satoshi
National Insitute for Fusion Science
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SAKAKIBARA Satoru
National Insitute for Fusion Science
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SAKAMOTO Ryuichi
National Insitute for Fusion Science
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TANAKA Kenji
National Insitute for Fusion Science
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WATANABE Kiyomasa
National Insitute for Fusion Science
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YAMADA Ichihiro
National Insitute for Fusion Science
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MOTOJIMA Osamu
National Insitute for Fusion Science
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SUZUKI Yasuhiro
National Institute for Fusion Science, Toki 509-5292, Japan
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MIYAZAWA Junichi
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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KOBAYASHI Masahiro
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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MORISAKI Tomohiko
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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MICHAEL Clive
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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the LHD
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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Suzuki Yasuhiro
National Agriculture And Food Res. Organization (naro) National Inst. Of Crop Sci.
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Tanaka Kenji
National Food Institute
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Morita Shigeru
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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OHYABU Nobuyoshi
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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SAKAMOTO Ryuichi
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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YAMADA Ichihiro
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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WATANABE Kiyomasa
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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MOTOJIMA Osamu
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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OHDACHI Satoshi
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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MIYAZAWA Junichi
National Institute for Fusion Science
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KOBAYASHI Masahiro
National Institute for Fusion Science
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FUNABA Hisamichi
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
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